This is a question that we see on Engineers Edge occasionally. An engineering answer is impractical for a volunteer as that would require a significant amount of work -modeling, questions, right software, detail drafting, materials, etc.
My guess? 40 + hours for an experienced analysis engineer who happens to have the right expensive software. You're unlikely to get the help you are asking for.
My quick glance - it's strong enough to support properly installed solar panels, use marine grade aluminum and navigate the boat clear from hurricanes.